Sustainability of Mediterranean Deltaic and Lagoon Wetlands with Sea-Level Rise: The Importance of River Input

• Published in: Estuaries and coasts 2011-05, Vol.34 (3), p.483-493
• Main Authors: Day, John, Ibáñez, Carles, Scarton, Francesco, Pont, Didier, Hensel, Philippe, Day, Jason, Lane, Robert
• Format: Article
• Language: English
• Subjects: Accretion; Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Brackish water ecosystems; Coastal Sciences; Deltas; Earth and Environmental Science; Ecology; Elevation; Environment; Environmental Management; Environmental Sciences; Estuaries; Fresh water ecosystems; Freshwater; Freshwater & Marine Ecology; Fundamental and applied biological sciences. Psychology; Lagoons; Marine; Marshes; River deltas; River water; Rivers; Sea level; Sea level rise; Sediments; Subsidence; Sustainability; Synecology; Topographical elevation; Water and Health; Wetlands
• ISSN: 1559-2723; 1559-2731
• DOI: 10.1007/s12237-011-9390-x

We report on a decadal trend of accretionary dynamics in the wetlands of several northwestern Mediterranean deltas and a lagoon system, all of them with high rates of wetland loss. Wetland vertical accretion and surface elevation change were measured at 55 riverine, marine, and impounded sites in four coastal systems: the Ebro delta, Spain; the Rhône delta, France; and the Po delta and Venice Lagoon, Italy. Vertical accretion and elevation change ranged between 0 and 25 mm year⁻¹ and were strongly correlated. The highest rates of elevation gain occurred at riverine sites where vertical accretion was highest. We conclude that areas with high sediment input, mainly riverine, are the only ones likely to survive accelerated sea-level rise, especially if recent higher estimates of 1 m or more in the twenty-first century prove to be accurate. This is the first study where the importance of river input on wetland survival has been demonstrated at a decadal time scale over a broad geographical area.